One of the more extreme government abuses of the post-9/11 era targets U.S. citizens re-entering their own country, and it has received far too little attention. With no oversight or legal framework whatsoever, the Department of Homeland Security routinely singles out individuals who are suspected of no crimes, detains them and questions them at the airport, often for hours, when they return to the U.S. after an international trip, and then copies and even seizes their electronic devices (laptops, cameras, cellphones) and other papers (notebooks, journals, credit card receipts), forever storing their contents in government files. No search warrant is needed for any of this. No oversight exists. And there are no apparent constraints on what the U.S. Government can do with regard to whom it decides to target or why.

In an age of international travel -- where large numbers of citizens, especially those involved in sensitive journalism and activism, frequently travel outside the country -- this power renders the protections of the Fourth Amendment entirely illusory. By virtue of that amendment, if the government wants to search and seize the papers and effects of someone on U.S. soil, it must (with some exceptions) first convince a court that there is probable cause to believe that the objects to be searched relate to criminal activity and a search warrant must be obtained. But now, none of those obstacles -- ones at the very heart of the design of the Constitution -- hinders the U.S. government: now, they can just wait until you leave the country, and then, at will, search, seize and copy all of your electronic files on your return. That includes your emails, the websites you've visited, the online conversations you've had, the identities of those with whom you've communicated, your cell phone contacts, your credit card receipts, film you've taken, drafts of documents you're writing, and anything else that you store electronically: which, these days, when it comes to privacy, means basically everything of worth.